Re: [PATCH v10 04/21] aio-wait.h: introduce AIO_WAIT_WHILE_UNLOCKED

[Kevin Wolf <kwolf@redhat.com>]

Am 25.07.2022 um 09:38 hat Emanuele Giuseppe Esposito geschrieben:
> Same as AIO_WAIT_WHILE macro, but if we are in the Main loop
> do not release and then acquire ctx_ 's aiocontext.
> 
> Once all Aiocontext locks go away, this macro will replace
> AIO_WAIT_WHILE.
> 
> Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
> ---
>  include/block/aio-wait.h | 17 +++++++++++++----
>  1 file changed, 13 insertions(+), 4 deletions(-)
> 
> diff --git a/include/block/aio-wait.h b/include/block/aio-wait.h
> index 54840f8622..a61f82c617 100644
> --- a/include/block/aio-wait.h
> +++ b/include/block/aio-wait.h
> @@ -59,10 +59,13 @@ typedef struct {
>  extern AioWait global_aio_wait;
>  
>  /**
> - * AIO_WAIT_WHILE:
> + * _AIO_WAIT_WHILE:
>   * @ctx: the aio context, or NULL if multiple aio contexts (for which the
>   *       caller does not hold a lock) are involved in the polling condition.
>   * @cond: wait while this conditional expression is true
> + * @unlock: whether to unlock and then lock again @ctx. This apples
> + * only when waiting for another AioContext from the main loop.
> + * Otherwise it's ignored.
>   *
>   * Wait while a condition is true.  Use this to implement synchronous
>   * operations that require event loop activity.
> @@ -75,7 +78,7 @@ extern AioWait global_aio_wait;
>   * wait on conditions between two IOThreads since that could lead to deadlock,
>   * go via the main loop instead.
>   */
> -#define AIO_WAIT_WHILE(ctx, cond) ({                               \
> +#define _AIO_WAIT_WHILE(ctx, cond, unlock) ({                      \

"All identifiers that begin with an underscore and either an uppercase
letter or another underscore are always reserved for any use." (C11,
7.1.3)

Kevin